I have known people who like to sit around listening to police scanners to see what is going on near them. There is an app for the iPhone already from Juicy Development that lets the iPhone be used as a police scanner. That app is now available for the Android platform.
The app is called Police Scanner for Android and lets the user hear police, fire, and EMS activities around the world. The scanner uses adaptive technology to post live streams a few hours after changes.
The scanner can pick up over 2,300 national and international EMS streams and offers the largest selection of fire, police, and emergency services streams available for Android. The app can be downloaded now for $2.99.